New rebuild, clogged oil passage!

Mountainman · **Posted:** Fri Jan 17, 2020 7:19 pm

I finally got back after this stubborn Italian girl, and solved it.

1. #2 injector was dumping fuel like crazy and I was trying to compress ounces of fuel. Lucky i didnt bend a rod, but i broke a starter gear!

2. Still no oil pressure though. So I finally pulled the front pump and there's a large oil gallery plug behind the pump cover where I was able to put a 3/8" fuel hose in, and blow through it, and with the filter off, air passed through so well you could hear it.

3. Went back to my vapor lock theory, and it pulled oil easily without the filter on ... replacing the oil pump in vehicle (in frame that is) wasn't bad. It runs well now.

,-i was able to verify that the over pressure spring was there, but not its function.

TKB4 · **Posted:** Fri Jan 17, 2020 10:12 pm

I generally add some Seafoam for about 25 to 50 miles or at least run a few minutes before changing the oil and filter.

WWDiesel · **Posted:** Fri Jan 17, 2020 11:47 pm

Mountainman wrote:

I finally got back after this stubborn Italian girl, and solved it.
1. #2 injector was dumping fuel like crazy and I was trying to compress ounces of fuel. Lucky i didnt bend a rod, but i broke a starter gear!
2. Still no oil pressure though. So I finally pulled the front pump and there's a large oil gallery plug behind the pump cover where I was able to put a 3/8" fuel hose in, and blow through it, and with the filter off, air passed through so well you could hear it.
3. Went back to my vapor lock theory, and it pulled oil easily without the filter on ... replacing the oil pump in vehicle (in frame that is) wasn't bad. It runs well now.
,-i was able to verify that the over pressure spring was there, but not its function.

So are you saying the oil pump was the problem all along? :shock:

Mountainman · **Posted:** Sat Jan 18, 2020 1:19 am

WW, basically yes. Plus the injector that was dumping fuel like crazy.
But, the new oil pump couldn't draw oil until I pulled the filter either, so they must cavitate until primed. I would just count on leaving the filter off and cranking for a few seconds to prime the pump. It shoots about a cup of oil out on the deck, but then it did its job well and the oil light turns off within 3 seconds of cranking. My jeep with almost a quarter million miles takes 6 seconds of cranking (injector fuse pulled in both cases).

This was with both orings on the oil pickup being new. So, it shouldn't have had anywhere to draw air from.

WWDiesel · **Posted:** Sat Jan 18, 2020 4:38 am

Mountainman, that is kinda weird. Guess the oil pump was air locked and could not overcome the resistance of pumping against the closed system?
Makes me think of some Buick engines we used rebuild in our shop years ago that had the oil pump made inside the front aluminum timing cover. (stupid design)
We always had to pack the insides of new oil pump housing and around the gears full with lightweight grease to make it prime on first startup.
If you did not pack it, it would never pick up the oil and prime when you started the engine after rebuilding.

My66dodge · **Posted:** Sat Jan 18, 2020 9:09 am

X2 with the oil pump priming, if you can’t spin up the oil pump like on a small block without turning the engine or even if you can, I always pack the pump with grease, I have diagnosed many power stroke 7.3’s with in ability to prime and packed them with grease to get them running

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Mountainman · **Posted:** Sat Jan 18, 2020 11:52 am

Thanks fellas. I got the same story from my brother in law who's a long time master mechanic. I'll figure these things out eventually...

WWDiesel · **Posted:** Sat Jan 18, 2020 2:22 pm

Mountainman wrote:

Thanks fellas. I got the same story from my brother in law who's a long time master mechanic. I'll figure these things out eventually...

Any oil pump that sets above the top of the oil sump level should be packed with lightweight grease to insure priming on new oil pump installs or when rebuilding an engine and everything has been thoroughly drained.

Many old time rebuilders use Vaseline Petroleum jelly or a similar lightweight grease.
Vaseline will create the seal needed for vacuum to draw or suck the oil into the oil pump. The Vaseline will quickly be dissolved into the oil.
Engine assembly lube should be used all moving/rotating parts. The goal is to sufficiently coat all moving parts to protect them during the critical first few minutes of engine run time until the oil pump can pick up the oil and create lubrication pressure & flow to all the critical parts.
When the pump spins for the first time on start up, vacuum is created in the oil pump housing to draw/suck the oil up into the oil pump and then push it through the entire lubrication system along with filling all the oil galleys, ports, oil filter, and oil cooler until they are completely filled with oil and pressurized as backpressure is created.

Mountainman · **Posted:** Sat Jan 18, 2020 5:01 pm

Makes sense. I made the mistake of thinking that the oil pump is below the oil level. It looks that way, but not enough apparently :banghead:

New rebuild, clogged oil passage!

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